Compass Swing

[rakesb]

I'm based at KTBN in east-central Missouri. Can anyone recommend a nearby authorized repair station to install and swing a new vertical card magnetic compass to replace the faltering windscreen divider mounted "whiskey" compass in my 1966 M20C? A nearby airport with a surveyed and calibrated compass rose? Master compass? Transit-pelorus? Advice? Concerns?

[Cody Stallings]

Precision @ KBVX. They are a Avionics Repair station... Good shop.

[N601RX]

Your local A&P?

[Jerry 5TJ]

If all three GPS fail I might look at the vertical card compass.

Probably I'd just use the iPad GPS instead.
If it were not required equipment I'd consider removing the whisky compass.
Seriously, what is it good for in 2014?  

I generally set the DG to track and not magnetic heading unless there's a heck of a cross-wind.
The last time I looked closely at it flight was when it leaked kerosene on my pant leg.

[Hector]

If all three GPS fail I might look at the vertical card compass. Probably I'd just use

the iPad GPS instead.

If it were not required equipment I'd consider removing the whisky compass.

Seriously, what is it good for in 2014?

The last time I looked at it flight was when it leaked kerosene on my pant leg.

Don't know. I set my DG to the vertical compass every 30 minutes at the same time I switch fuel tanks. I have three separate GPS's in the plane but they show you track, not heading.

Sent from my iPad using Tapatalk HD

[Rwsavory]

Dyersburg Avionics in Caruthersville, MO. A full service shop and very helpful.

[Marauder]

I'm based at KTBN in east-central Missouri. Can anyone recommend a nearby authorized repair station to install and swing a new vertical card magnetic compass to replace the faltering windscreen divider mounted "whiskey" compass in my 1966 M20C? A nearby airport with a surveyed and calibrated compass rose? Master compass? Transit-pelorus? Advice? Concerns?

I have the PAI-700 vertical card compass. I needed to install the balancing ball kit on mine to get it swung correctly. Our steel roll cage can be magnetized and short of degaussing it, offsetting it is the only alternative.

http://www.cumulus-soaring.com/precision/Bulletin_IC-102.pdf

http://www.chiefaircraft.com/aircraft/flight-instruments/magnetic-compasses/pcn-pbb475.html

[rakesb]

Most A&Ps aren't authorized to work on, and sign off on, instruments, right?

Your local A&P?

[cliffy]

A&Ps can remove and install instruments but can not repair them. That means that they can not replace the rubber diaphragm on wet compasses and refill them as we did for decades before the new rulings. They can however "swing" a compass.

[N601RX]

Most A&Ps aren't authorized to work on, and sign off on, instruments, right?

They can install and wire up instruments and avionics, they just can't open the instruments up and repair them. Other than that the only thing the repair station can do that an IA can't is certify a transponder installation. Their rates are usually quit a bit cheaper also.

[Piloto]

Best way to swing a compass is in-flight. Find on Google Earth a true Noth-South East-West oriented roads in your vicinity. Most farms road are true north oriented. Fly the plane along the true North oriented road and adjust the gyro for a corresponing magnetic north indication. Fly the plane for gyro North South East and west and adjust the compass. Verify gyro setting with road after several turns. I found in-flight swing to be quicker and more accurate than ground swing.

 

José 

[Mooneymite]

If you have a big ramp, you can use your GPS to give you a magnetic track. On the ground you can use that to check/align your mag compass. On a runway, use those little, tiny numbers on the Jepp chart for precise runway mag heading. I've found the GPS easier to use than those painted compass roses.

[DonMuncy]

Jose,

I think you are right, with the added benefit of having all your flight parameters (engine at power and radios, etc. on) figured into the adjustment. I assume you have to do it in a "no wind" situation. Otherwise you would have to align your plane with the road no matter your track, which might be difficult.

[rakesb]

Thank you everyone. My local A&P is willing to install, wire, and swing the compass for me. Now, I just need a nearby (to KTBN) airport with a surveyed and calibrated compass rose. Anyone know of such an airport?

[carusoam]

There is an official way to look that up along with other important airport details....

Best regards,

-a-

[N201MKTurbo]

This may sound kind of crude, but it works.

Get a military/hiking compass with the sights. Stand about 50 feet away from the plane so nothing is affecting the compas and align the sights nose to tail. Adjust the plane till it is aligned the way you want.

[rakesb]

Precision @ KBVX. They are a Avionics Repair station... Good shop.

Thank you, Cody. I'll add them to my list of potential resources. -- v/s, Bobby

[rakesb]

If all three GPS fail I might look at the vertical card compass. Probably I'd just use

the iPad GPS instead.

If it were not required equipment I'd consider removing the whisky compass.

Seriously, what is it good for in 2014?

The last time I looked at it flight was when it leaked kerosene on my pant leg.

Thank you, Jerry. Yes, my sympathies exactly. I have a yoke-mounted Garmin GPSMAP 295, and I just received an iPad Mini from my wife for my birthday and Christmas, but I just feel uncomfortable without a working compass. -- v/s, Bobby

[rakesb]

Dyersburg Avionics in Caruthersville, MO. A full service shop and very helpful.

Thank you; I'll add them to my list of potential resources. -- v/s, Bobby

[rakesb]

I have the PAI-700 vertical card compass. I needed to install the balancing ball kit on mine to get it swung correctly. Our steel roll cage can be magnetized and short of degaussing it, offsetting it is the only alternative.

http://www.cumulus-soaring.com/precision/Bulletin_IC-102.pdf

http://www.chiefaircraft.com/aircraft/flight-instruments/magnetic-compasses/pcn-pbb475.html

Thank you; I'll probably need the balancing balls kit because N6094Q is an older M20C with a flat windscreen divider, but hopefully that will be a permanent solution to the magnetism problem, whereas degaussing would probably require periodic repeats. -- v/s, Bobby

[rakesb]

Best way to swing a compass is in-flight. Find on Google Earth a true Noth-South East-West oriented roads in your vicinity. Most farms road are true north oriented. Fly the plane along the true North oriented road and adjust the gyro for a corresponing magnetic north indication. Fly the plane for gyro North South East and west and adjust the compass. Verify gyro setting with road after several turns. I found in-flight swing to be quicker and more accurate than ground swing.

 

José

Thank you, Jose; the prospect of repeatedly repositioning the aircraft on the ground does seem a bit awkward and time-consuming compared to the ease of making a series of 90-degree turns in flight. -- v/s, Bobby

[rakesb]

Best way to swing a compass is in-flight. Find on Google Earth a true Noth-South East-West oriented roads in your vicinity. Most farms road are true north oriented. Fly the plane along the true North oriented road and adjust the gyro for a corresponing magnetic north indication. Fly the plane for gyro North South East and west and adjust the compass. Verify gyro setting with road after several turns. I found in-flight swing to be quicker and more accurate than ground swing.

 

José

If you have a big ramp, you can use your GPS to give you a magnetic track. On the ground you can use that to check/align your mag compass. On a runway, use those little, tiny numbers on the Jepp chart for precise runway mag heading. I've found the GPS easier to use than those painted compass roses.

Thank you; I'll be sure to check my Garmin GPSMAP 295 and iPad Mini for their magnetic track capabilities. -- v/s, Bobby

[rakesb]

There is an official way to look that up along with other important airport details....

Best regards,

-a-

Is there an index to compass roses in the A/FD? Is the FAA's digital A/FD data searchable for compass roses? -- v/s, Bobby

[rakesb]

This may sound kind of crude, but it works.

Get a military/hiking compass with the sights. Stand about 50 feet away from the plane so nothing is affecting the compas and align the sights nose to tail. Adjust the plane till it is aligned the way you want.

No, not at all, if it's a legal technique for swinging a compass. I work at Fort Leonard Wood, so I can probably borrow a calibrated, high quality compass, transit, or GPS. -- Thank you, Bobby

[carusoam]

Bobby,

I think the AFD has it. I recall that there were about 10 airports per state that had them. But that is an ancient memory, the details are beyond fuzzy... I rely on my MSC for help with those kind of things now....

My C had the compass mounted on center tube. When turning 360degrees using the compass, it would hang, and then accelerate to catch up...

That's where my IFR training in my own plane went on hold.... A new compass did the same thing. I could not tell if my center tube was the modern SS or the usual tubing.

Best regards,

-a-